Have signs of alien life entered into our orbit? Avi Loeb, a Harvard University astrophysicist, says yes.
“Our civilization has sent five man-made objects into interstellar space: Voyager 1 and Voyager 2, Pioneer 10 and Pioneer 11, and New Horizons,” Loeb writes in his upcoming book Extraterrestrial: The First Signs of Intelligent Life. The book will be released on January 26.
“And if other civilizations developed out there among the stars, wouldn’t they have felt that same urge to explore, to venture past familiar horizons in search of the new? Judging by human behavior, that would not be surprising in the least.”
This stance has gained Loeb a certain level of notoriety, and criticism. He's recently claimed — and reiterates this claim in his book — that the odd-shaped, rocky object that passed through our Solar System known as 'Oumuamua was, in fact, a piece of abandoned alien technology — perhaps a once-operational "probe."
Who is Avi Loeb? — Aside from being a Harvard University professor, Loeb served as the chair of Harvard's astronomy department and founding director of Harvard's Black Hole Initiative. The astrophysicist has authored several books on cosmic objects such as galaxies and stars, as well as our search for alien life in the universe.
When it comes to the argument over extraterrestrial life, Loeb is clearly on the side of alien existence. In recent interviews and his book, Loeb argues 'Oumuamua is a relic of a now-annihilated alien civilization.
What is 'Oumuamua?
On October 19, 2017, our Solar System received an unexpected visitor. A rocky, elongated object, sort of shaped like a cigar, visited from beyond the realms of the Sun — the first-ever recorded interstellar object to cruise through our neck of the galaxy.
Oumuamua was unlike anything astronomers had ever observed before.
The cosmic object was originally classified as a comet, but later observations showed no cometary activity as it lacks the telltale coma (or envelope surrounding a comet’s core) and necessary tail of gas and dust. It also has a dry surface, making it more similar to a rocky asteroid.
However, it also can't be an asteroid given its acceleration as it sped by the Sun. 'Oumuamua slingshotted past the Sun at a speed of 196,000 miles per hour — which is too fast to be explained by the pull of the Sun's gravity alone.
‘Oumuamua is also highly elongated, believed to stretch across 900 feet in its longest dimension.
Another cosmic mystery? Astronomers reason 'Oumumua roamed space for hundreds of millions of years before its chance encounter with the Solar System. However, while it seems to have come from the direction of Vega, one of the stars that make up the Lyra Constellation, its trajectory shows that it would have been at the star's location around 300,000 years ago.
However, back then, Vega would have been in a different location.
But is it aliens? — In 2018, Loeb co-authored a paper published in The Astrophysical Journal Letters arguing that Oumuamua's speed and acceleration, as well as its brightness, suggests it is not a natural object but instead a piece of advanced technology created by a distant alien civilization.
Loeb's argument garnered him criticism from his fellow astrophysicists, many of who dismissed his claims as ludicrous.
"No, 'Oumuamua is not an alien spaceship, and the authors of the paper insult honest scientific inquiry to even suggest it," Paul Sutter, an astrophysicist at Ohio State University, wrote on Twitter.
Loeb responded with a book. In Extraterrestrial: The First Signs of Intelligent Life, Loeb suggests that 'Oumuamua is essentially alien scrap that had been traveling through the cosmos, quite possibly from a long-dead alien civilization.
He argues that the object's strange acceleration can only be explained by physical production, and reasons if the beings who created the object were capable of designing advanced technology they are also likely "vulnerable to annihilation by self-inflicted wounds."
"'Oumumua must have been designed, built, and launched by an extraterrestrial intelligence," he writes.
How do we look for aliens?
If 'Omuamua is not a sign of aliens, are there other signs out there?
One of the biggest questions astronomers hope to answer is whether or not we are alone in the universe. As a result, scientists strive to look for hints of alien life in the cosmos by sending out probes and spacecraft to distant worlds.
However, scientists are not exactly sure what that alien life would look like if we did happen to stumble upon it.
Our most concentrated efforts to look for extraterrestrial life is on Mars, where robotic astrobiologists are currently hunting for evidence of the ancient microbial life that may have once thrived there.
However, when it comes to finding life developed past the microbial stage, scientists are at a bit of a loss of what to look for. Would they look like humans? Will life have developed a different way? Would they be advanced enough to communicate back to us? And, just perhaps, would they have flung a giant cigar-shaped rock in our direction?
When it comes to extraterrestrial life, the possibilities are endless and largely obscure.
In June 2020, researchers estimated there could be 30 intelligent civilizations in the Milky Way galaxy. However, the researchers estimate that these extraterrestrial civilizations may be located around 17,000 light-years away, which would make it hard to detect or communicate with them with our current technology.
Another study, published in August 2020, looked for signs of alien life in 10 million star systems but came up empty-handed.
And yet, our search for alien life continues.
What's next for the search? — For Loeb, his book is just the beginning.
The astrophysicist is also serving as an adviser on the Breakthrough Starshot Initiative, a project aimed at developing ultra-fast light-driven nano-crafts. These may serve as interstellar probes to distant worlds — much like Loeb argues 'Oumuamua was.
Meanwhile, astronomers are still pouring over data collected of 'Oumuamua. The mysterious object has already made its way through the Solar System, never to be seen again by us on Earth.